JPS6342917A - Production of fiber with adsorption activity - Google Patents

Abstract

PURPOSE:To produce the title fiber which is suitable for deodorizing diapers or pillow covers, by wet-spinning through nozzles, an aqueous dope containing a particular adsorbent of specific particle sizes and a uster-soluble alginate salt. CONSTITUTION:A particular adsorbent of particle sizes smaller than 0.9 time the diameter of the spinning nozzle such as activated carbon or activated alumina is thoroughly mixed with a water-soluble alginate salt such as lithium alginate to prepare an aqueous dope. The dope is extruded through spinning nozzles into a coagulation bath containing, e.g., aqueous calcium chloride to give alginate fiber containing an adsorbent. The bundles of the fibers are interlaced to give the objective fiber.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a method for producing adsorption active fibers.

More specifically, the present invention provides deodorization, deodorization, and harmlessness by adsorption and removal of fine particles, odor components, and harmful components in the air, as well as metal ions, nonionic trace components, malodorous components, and harmful components in liquids. The present invention relates to a method for efficiently producing adsorptive active fibers made of alginic acid fibers containing an adsorbent, which are suitably used for chemical reactions, etc.

BACKGROUND OF THE INVENTION In recent years, textile products with adsorption functions have been widely used in many fields including environmental hygiene. For example, sanitary materials for the elderly, sanitary materials with deodorizing and deodorizing functions, and special horticultural vegetables and fruits in horticultural production areas, which are needed to improve the living environment hygiene and nursing care of bedridden elderly in an aging society. It is used in transportation supplies to prevent foreign odors and maintain freshness, filters for deodorizing, deodorizing, and decolorizing industrial wastewater and exhaust gas, and odor-proof wrapping paper for refrigerator storage.

Conventionally, fiber products with adsorption functions used for these purposes have been made by mixing activated carbon fibers, which themselves have adsorption functions, or granular or amorphous adsorbents with short fibers that have sheet-forming properties. Activated carbon paper, zeolite paper, Amion paper, etc., which have an adsorption function by filling the pores formed by intertwining fibers with the adsorbent, are known.

Problems to be Solved by the Invention Among these conventionally known fiber products with an adsorption function, activated carbon fiber has a low single fiber strength, and even when formed into a sheet '6, it does not have sufficient strength. In addition, the adsorbent paper filled with pores formed by intertwining the adsorbent with the fibers cannot freely control the 5 pores, and the adsorbent does not separate from the fibers. It has the disadvantage that it easily falls off or scatters due to friction.

It is also known to granulate adsorbents with various binders and mold them, but since these binders do not have fiber-forming properties, they cannot be molded into fibers.

The present invention improves the drawbacks of conventional textile products with adsorption functions, has strong single fiber strength, prevents the adsorbent from falling off or scattering due to friction, and has an extremely active adsorption function. The purpose of this invention is to provide a fiber product with excellent adsorption activity, which also has a filtering effect such as the removal of fine particles.

Means to Solve the Problem By the way, alginic acid is a linear polymer consisting of α-(1,4)-L-guluronic acid and β-(1,4)-D-mannuronic acid. It is one species and widely exists in the natural world as cell membranes and intercellular materials of seaweeds, especially brown algae. Currently, this alginic acid is used as a relatively inexpensive industrial raw material in the food field as an ice cream stabilizer, thickener, emulsion stabilizer, beer foam retention stabilizer, etc., and in the textile field as a spinning paste, printing paste, It is widely used in finishing pastes and as a sizing agent in the paper manufacturing field.

On the other hand, alginate alkali salts are known to have poor spinnability, and long fibers of water-insoluble salts are currently used as surgical fibers. It is also known that these long fibers can be used as non-woven fabrics or knitted fabrics, and it is also known that paper can be made from alginate fibers.

As a result of extensive research in order to develop adsorption active fibers with excellent performance, the present inventors focused on the alginic acid and developed an aqueous system containing a granular adsorbent with a specific particle size and a water-soluble alginate. It was discovered that alginic acid fibers containing an adsorbent obtained by wet spinning dope are suitable for the above purpose, and based on this knowledge, the present invention was completed.

That is, the present invention prepares an aqueous dope containing a granular adsorbent and a water-soluble alginate whose particle size is 0.9 times or less than the diameter of a spinning nozzle discharge hole, and then introduces this dope into a coagulation bath through a spinning nozzle. The present invention provides a method for producing adsorption-active fibers comprising alginic acid fibers containing an adsorbent, which is characterized by wet spinning.

The present invention will be explained in detail below.

The particle diameter of the granular adsorbent used in the method of the present invention needs to be 0.9 times or less the discharge diameter of the spinning nozzle. If a granular adsorbent with a particle diameter exceeding 0.9 times is used, the nozzle will be at least partially blocked during spinning, and the dope ejection direction will not be perpendicular to the nozzle surface, causing the dope released to the surface to become Since the fibers solidify while remaining partially attached, the resulting fiber surface has irregularities, which impairs smoothness when a sheet is formed.

The amount of this granular adsorbent added is preferably an amount that does not interfere with the formation of a continuous system when spinning the dope, and this amount largely depends on the specific gravity of the adsorbent, but in general, it is It is selected within a range of 50 inches or less, preferably 30% or less of the volume.

Particulate adsorbents include, for example, activated carbon, activated alumina, activated silica, zeolite, bentonite, acid clay, amion, and cristobalite toca.

Examples of the water-soluble alginate include monovalent alkali salts such as lithium salt, sodium salt, potassium salt, and ammonium salt of alginic acid. These water-soluble alginates may be used alone or in combination of two or more, and the concentration in the aqueous dope is usually 100 to 12/2, depending on the degree of polymerization.
selected within the range of l.

In the method of the present invention, the aqueous dope may contain, for example, carboxymethyl cellulose, marten powder, carrageenan, pullulan, etc., within a range that does not interfere with spinning and entrapment of the granular adsorbent.
It can contain polysaccharides such as pectin, water-soluble synthetic polymers such as polyoxymethylene, sodium polyacrylate, polyacrylamide, polyvinyl alcohol, and water-soluble proteins such as gelatin and albumin.

In the method of the present invention, a solution containing a water-soluble salt of a metal ion or an organic or inorganic acid which exchanges with the cations of water-soluble alginate to make it insolubilized is used as the coagulation bath. Examples of such water-soluble salts include calcium,
Hydrochlorides, sulfates, nitrates, phosphates of metals such as barium, strontium, aluminum, zinc, nickel, cobalt, chromium, copper, manganese, lead, etc. Organic or inorganic acids such as acetic acid, propionic acid, hydrochloric acid, sulfuric acid etc. can be mentioned. These water and packaging salts may be used alone or in combination of two or more.

In this coagulation bath, hydrophilic organic solvents such as methanol, ethanol, acetone, ethyl acetate, ethyl formate, acetate amide, formate amide, and various surfactants are added in order to completely modify the fiber surface, if necessary. can do.

In the method of the present invention, the aqueous dope is quantitatively extruded using a gear pump or the like into the coagulation bath through a spinning nozzle equipped with a large number of discharge holes, thereby producing alginic acid fibers completely encased in the adsorbent. Wet spun.

The adsorption active fibers made of alginate fibers containing the adsorbent thus obtained can be prepared by the following method.
It can be a non-woven fabric or a paper-like sheet.

In other words, the method for manufacturing a nonwoven fabric is, for example, by spreading the fibers into a two-dimensional sheet in a small amount of water and randomly intertwining the fibers, so that the gel fibers bind to each other and form a random sheet. As a network is formed,
By drying this, a nonwoven fabric made of fibers containing the adsorbent can be obtained.

On the other hand, regarding the method for producing a paper-like sheet, for example, the fibers are 1.0 to 2Q, Qmi+, preferably 2.0 to 10.
Cut into short fibers of 0yIIm, either alone or mixed with short fibers such as cellulose pulp, rayon, polyolefin, polyester, polyacrylic, polyamide, etc., and if necessary, use a binder, and wet-process by a known method. By drying the obtained wet paper after papermaking, a paper-like sheet made of fibers containing an adsorbent can be obtained.

The adsorptive active fibers obtained by the method of the present invention and the nonwoven fabrics and paper-like sheets made using the same are as follows: (1) Since the adsorbent is included in the fibers, the alginic acid molecules on the fiber surface are Since it has the ability to form bonds between fibers, it is possible to self-adhere without a binder if appropriate conditions are selected during sheet formation. (2) Since it retains much of the strength of alginate fibers, activated carbon fiber The single fiber strength is much greater than that of fibers that themselves have an adsorption function, such as (3) ff
It can have both the function of alginic acid that makes up fibers and the function of a comprehensive adsorbent. For example, in the case of physiological hygiene materials, it is possible to have both the hemostatic function of alginic acid and the adsorption function of an adsorbent. (4) As the adsorbent, it is possible to use an adsorbent with a dramatically large specific area, so it is possible to maintain an extremely large adsorption activity. (5) By intertwining the adsorbent with fibers, Unlike adsorbent paper that fills the formed pores, this paper-like sheet can freely control the pores in the same way as conventional paper, so it has a filter effect such as removing fine particles, and has an adsorption effect. It has excellent characteristics such as the agent does not fall off or scatter from the fibers due to friction etc. ◇ Effects of the Invention The adsorptive active fibers obtained by the method of the present invention can be easily made into non-woven fabrics or paper-like sheets. Since these have the above-mentioned characteristics, they can be eliminated by adsorption and removal of fine particles, odor components, and harmful components in the air, as well as metal ions, nonionic trace components, malodorous components, and harmful components in liquids. Suitable for use in odor removal, detoxification, etc.

Specifically, it is used as a base for sanitary materials for the elderly such as deodorizing disposable diapers, mats, pillow cases, and underwear, menstrual hygiene materials, and transportation supplies for preventing off-odors and preserving the freshness of special garden vegetables and fruits in horticultural production areas. It can be suitably used for filters for deodorizing, deodorizing, and decolorizing fibers, paper, nonwoven fabrics, etc., industrial wastewater, exhaust gas, etc., and deodorizing wrapping paper for storage in refrigerators.

Example Next, the present invention will be explained in more detail with reference to Examples.

Example 1 Activated carbon fine powder with a particle size of 15 μm or less - [Manufactured by Takeda Pharmaceutical Co., Ltd., FP-L, Dp 3.4 μm, maximum 12 μm] 12
? After adding it to a kneader containing f6t of water and dispersing it uniformly, sodium alginate [manufactured by Kimitsu Chemical Industry ■, type H1 molecular weight 6.3 x 10" Dalton 124
C1i was added little by little and thoroughly mixed to prepare a dope of sodium alginate in which activated carbon was incorporated.

Next, this dope was filtered through a ceramic filter with pores of 50 μm or less to remove foreign substances, and then the filtered dope was transferred to a stock solution supply tank of a sty wet spinning machine and left under reduced pressure overnight to defoam.

Then, the dope was discharged at a speed of 13,777 min.
So, there are 1000 circular pores of 0.10 mm ffi! The first, second and third gossets were spun through a nozzle containing 21.0, 21.5 and 25.5, respectively, into a coagulation bath consisting of a 5 weight group calcium chloride aqueous solution. It was rotated and wound up at a speed of Orpm. A water bath was used for both the second bath and the third bath. The stretching ratio is 1.19. No clogging of the nozzle holes by activated carbon was observed at all, and calcium alginate fibers were obtained in which about 5% by weight of activated carbon was entrapped in the total fibers.

Next, the fiber bundle obtained in this way was cut into a length of 30 m, suspended in a small amount of water, and made into a gauze shape so that the fibers were intertwined in the direction perpendicular to the axis and the fibers were not densely arranged as much as possible. The fibers were stretched and dried to produce a nonwoven fabric made of fibers completely encased in activated carbon.

On the other hand, the fibers were cut into lengths with a fiber length of 3 and a thickness of Q m, and water was added so that the fiber concentration was 0.15% by weight.
After disintegrating for 30 minutes in a disintegrator, undisintegrated fiber lumps were removed using a 6-cut flat screen. Next, J engineering 5
P8209 was used to create paper with a basis weight of approximately 609/m''.

These samples were subjected to ammonia adsorption test and J Engineering 5.
An iodine adsorption test was conducted according to K1474.

The results are shown in Table 1.

In addition, in the ammonia adsorption test, for sample 5.02,
Spray 200ppm ammonia water 5-f, 5.700
- After being left in a plastic bag for 3 hours, the air in the plastic bag was blown into Nessler's reagent 200rnt, and the degree of coloring of the solution due to ammonia was determined by absorbance at a wavelength of 400 nm.

, /' Example 2 In Example 1, copper zeolite [Nippon Kagaku Kogyo Co., Ltd., average particle size 0.3 to 0.8 μm or less] 12 was used instead of activated carbon.
Using r'i, calcium alginate fibers, nonwoven fabrics, and paper containing copper zeolite were prepared under almost the same conditions. In the case of paper, the density is 0.6? /su, and the specific bursting strength was 1.9. Ammonia adsorption tests and iodine adsorption tests were conducted on these samples. The results are shown in Table 2.

Claims (1)

[Claims] 1. Preparing an aqueous dope containing a granular adsorbent and water-soluble alginate having a particle size of 0.9 times or less the spinning nozzle discharge hole diameter, and then introducing this dope into a coagulation bath through a spinning nozzle to perform wet spinning. A method for producing adsorption-active fibers comprising alginate-based fibers containing an adsorbent, characterized by: